This invention relates to a method and an apparatus for diagnosis of anomaly of an atomic power plant on the basis of water chemistry data, and particularly to a method and an apparatus for water chemistry diagnosis of a boiling water atomic power plant suitable for detecting causes of anomaly to take countermeasures against them early.
Water quality control of a boiling water atomic power plant is carried out on the basis of on-line data obtained by continuously monitoring the conductivity, pH, etc. and off-line data obtained by chemical analysis of periodically grabbed sampling water, such as concentrations of corrosion products, chemical impurities, etc. In order to exactly detect anomalies of operating states of an atomic power plant and component apparatus members from fluctuations in water quality by the conventional water chemistry diagnosis system, only on-line data are not enough, but also off-line data are required, and thus water quality control operators bear a heavy burden during the fluctuations in water quality.
As a system for detecting anomalies taking place in the component apparatus members from water chemistry data, a method for diagnosing anomaly occurrences by comparing patterns of ion concentration increase and decrease in water at sampling points in the primary cooling water system of a nuclear reactor with standard patterns of each cause of anomaly prepared in advance is known, as disclosed in Japanese Patent Application Kokai (Laid-open) No. 59-60293. However, in actual plants there are not only externally intruded impurities, but also corrosion products in an ionic state in the water passing through the primary cooling system of an atomic plant, and thus the species of involved ions are so many that it is quite hard to exactly detect causes of anomaly only from the increase and decrease of ion concentrations.
Japanese Patent Application Kokai (Laid-open) No 61-68593 proposes to make overall control of water chemistry data and find anomalies of an atomic power plant with respect to water quality early by inputting water chemistry data of the atomic power plant into a data file through on-line or off-line and making overall data processing and discloses diagnosis of anomaly by comparison of water chemistry data having a chemical correlation, for example, conductivity and pH, as one example of diagnosis of anomaly, but the prior art neither specifically discloses how an anomaly is diagnosed by comparison of i.e. conductivity with pH, nor takes it into consideration to identify causes of anomaly on the basis of comparison of i.e. conductivity with pH. That is, water chemistry data contain information on the state of a plurality of component apparatus members and thus it is difficult to exactly identify causes of anomaly, that is, what anomaly takes place in which component apparatus member from comparison of conductivity with pH at one sampling point.